Commercially available automated equipment currently exists for analyzing the particulate or cell concentration in blood. This equipment measures either the interaction of the blood particles with electric fields or the interaction of the blood particles with visible radiation. Instruments which utilize electric fields for blood analysis require rather complex equipment while instruments utilizing optical analysis techniques are simpler. However, the simplicity found with optical instruments is frequently obtained at the expense of accuracy.
A disadvantage of utilizing optical equipment to analyze the particulate concentration in blood is the fact that the visible radiation intensity used to determine particulate concentration does not vary linearly with changes in particulate concentration. This is due to the fact that instruments using nephelometric and/or turbinometric phenomenon have non-linear characteristics as a result of random scattering of light. The non-linear response of the optical equipment to the particulate concentration makes the interpretation of the output data difficult and somewhat inaccurate. If instrumentation is added to the optical equipment to linearize its response, the simplicity of the optical equipment rapidly approaches that of the electric field instruments. Thus, a highly desirable goal in blood analysis is to develop a simple optical instrument not requiring elaborate instrumentation, which responds linearly to changes in particulate concentration.
It is therefore an object of this invention to provide simple optical equipment for automatically analyzing the particulate content in blood bearing solutions.
It is another object of this invention to provide optical equipment capable of simultaneously analyzing and detecting two constituents in blood bearing solutions.
It is a further object of this invention to provide an instrument capable of obtaining a linear reading of the degree of agglutination of red blood cells.
A still further object of this invention is to provide a technique for increasing the linearity of response of optical equipment used to determine the particulate concentration in whole blood and in other solutions.